This present invention relates to manufacture of electrochemical cells. More particularly, the present invention provides a method and device for fabricating a solid state thin film battery device. Merely by way of example, the invention has been provided with use of lithium based cells, but it would be recognized that other materials such as zinc, silver, copper and nickel could be designed in the same or like fashion. Additionally, such batteries can be used for a variety of applications such as portable electronics (cell phones, personal digital assistants, music players, video cameras, and the like), power tools, power supplies for military use (communications, lighting, imaging and the like), power supplies for aerospace applications (power for satellites), and power supplies for vehicle applications (hybrid electric vehicles, plug-in hybrid electric vehicles, and fully electric vehicles). The design of such batteries is also applicable to cases in which the battery is not the only power supply in the system, and additional power is provided by a fuel cell, other battery, IC engine or other combustion device, capacitor, solar cell, etc.
Common electro-chemical cells often use liquid electrolytes. Such cells are typically used in many conventional applications. Alternative techniques for manufacturing electro-chemical cells include solid state cells. Such solid state cells are generally in the experimental state, have been difficult to make, and have not been successfully produced in large scale. Although promising, solid state cells have not been achieved due to limitations in cell structures and manufacturing techniques. These and other limitations have been described throughout the present specification and more particularly below.
Solid state batteries have been proven to have several advantages over conventional batteries using liquid electrolyte in lab settings. Safety is the foremost one. Solid state battery is intrinsically more stable than liquid electrolyte cells since it does not contain a liquid that causes undesirable reaction, resulting thermal runaway, and an explosion in the worst case. Solid state battery can store more energy for the same volume or more energy for the same mass than conventional batteries. Good cycle performance, more than 10,000 cycles, and good high temperature stability also has been reported.
Despite of these outstanding properties of solid state batteries, there are challenges to address in the future to make this type of batteries available in the market. To exploit the compactness and high energy density, no metal housing or excessive substrate should be used. To be used in variety of applications such as consumer electronics or electric vehicle, other than the current application, RFID, large area and fast film deposition techniques at low cost should be developed.
From the above, it is seen that techniques for improving solid state cells are highly desirable.